This is the renewal of a very successful training program that has been active for 27 years. The goal of this program is to train talented young scientists for research careers in reproductive biology. The predoctoral program combines classroom work with seminars and state-of-the-art training in research laboratories. The postdoctoral fellows dedicate the majority of their time to research, but audit courses as needed, attend seminar series and audit a course on writing grants. Supported by over $12 million in research funds, the faculty members have been selected for interests and expertise that fall in three broad areas that cover key approaches to studying reproductive biology. These are: 1) the endocrine group;2) reproductive processes;and 3) transgenic animal studies. The endocrine group studies the mechanisms of action of molecules important for reproduction and particularly the function of steroid receptors and their associated coactivators and corepressors. The reproductive processes group studies the regulation of genes and biological processes in reproductive tissues and systems including ovary, testes, prostate, and mammary gland. The transgenic group uses transgenic approaches to knock out/over express proteins involved in reproduction to elucidate the roles of these proteins in vivo. Experimental approaches range from cutting edge techniques in molecular biology, protein chemistry, and microscopy to tissue specific knockouts using CRE recombinase, targeted over expression and regulated gene expression in mice facilitating analysis of reproductive function at all levels. The program is designed for five predoctoral students and with five postdoctoral fellows at various levels of experience. Assuming our current trainees complete 3 years and we fill new slots as they open, we anticipate having two trainees with 1 year of experience, one with 3, one with 4r, and one with 5 years in the first year of support. Predoctoral training is typically 5 years with the last 4 years of support from the grant. Postdoctoral training is for up to 3 years, but many fellows are awarded individual fellowships limiting their support on this grant. In addition to the research facilities of the individual laboratories, trainees have access to both departmental and school wide core facilities for cell culture, integrated microscopy, transgenic animals, real time RT-PCR, protein chemistry, mass spectrometry, flow cytometry, and the molecular biology computation resource. These provide state-of-the-art equipment and assistance in the use of these techniques. The problems associated with reproduction, the consequent health of the mother and newborn, as well as control of fertility have a major impact on the health of Americans and on the economy of the country as well as on the well being of individuals. This training program prepares young scientists to address these important problems.